Molten metal sampler

ABSTRACT

A cast sand cartridge for a sampling lance for molten metal comprises in one embodiment two cast sand half sections with opposed recesses which define a sample cavity. A refractory cement lining for the sample cavity and a refractory cement coating on the exterior of the half sections, secure the assembly together, provide a smooth surfaced sample and maintain the integrity of the half sections during immersion in a molten metal bath. The frangible character of the half section affords quick release of the sample when the sampling lance is removed from the molten metal bath.

United States Paten Falk MOLTEN METAL SAMPLER Primary Examiner-S. Clement Swisher 76 Inventor: Richard A. Falk 519 Westminster 1 Dr. waukesha 53186 Att0rneyHenry C. Fuller, Jr.

[22] Filed: July 24, 1972 l [57] ABSTRACT [21] Appl. No.: 274,352

A cast sand cartridge for a sampling lance for molten metal comprises in one embodiment two cast sand half [52] CL 73/4254 R, 73/DIG- 9, 117/52, sections with opposed recesses which define a sample 249/114 cavity. A refractory cement lining for the sample cav- [5 Int. Cl. n and a refractory cement coating on the exterior of of Search the ections ecure the assembly together pro- 117/5-2; 164/4, 33; 249/114, 160 vide a smooth surfaced sample and maintain the integrity of the half sections during immersion in a molten [56] References cued metal bath. The frangible character of the half section UNITED STATES PATENTS affords quick release of the sample when the sampling 1,471,053 10 1923 Moore 117 52 lance is removed from the molten metal bath 2,441,695 5/1948 Fea 249 114 3,604,270 9 1971 Falk l? 73/DI G. 9 8 Clams 7 D'awmg guns MOLTEN METAL SAMPLER BACKGROUND OF THE INVENTION SUMMARY OF INVENTION The invention provides a non-combustible, inexpensive, lightweight sampling lance of relatively low mass and a low specific heat which minimizes de-gassing or boiling and spattering of metal when the lance is immersed in a molten metal bath. In one embodiment, the sampling lance is an assembly of two cast sand half sections which have opposed recesses which define a sample cavity which forms a sample of the appropriate size and configuration. The half sections are dipped in refractory cement and secured together around a metal pipe or handle which is received in grooved end walls. The lance is then dipped in" refractory cement to provide an exterior refractory cement coating which strengthens the sand cartridge and prevents the formation of a skull on the lance. The refractory lining on the sample cavity provides a smooth surface on the sample.

In a modified embodiment, a steel liner can be employed for the cartridge interior. In some embodiments an entry port is cut in a cartridge wall to fill the sample cavity. In other embodiments a tube projects through a cartridge end wall for receiving and conveying molten metal to the cartridge'interior.

Further objects and advantages of the present invention will become apparent from the following disclosure.

DRAWINGS 3 FIG. 1 is a perspective view of a sampling lance in accordance with the invention with the refractory cement exterior coating partially broken away.

FIG. -2 is an enlarged longitudinal sectional view of the sampling lance shown in FIG. 1.

FIG. 3 is an exploded perspective view of the cast half sections and the handle shown in FIGS. 1 and 2.

FIG. 4 is a longitudinal sectional view of a modified embodiment of the sampling lance shown in FIGS. 1, 2, and 3.

FIG. 5 is a longitudinal sectional view of a further embodiment of the invention.

To assemble the half sections 12 and 14, and form the cartridge 11, each section 12, 14 is dipped in a slurry of refractory cement 33. The cement 33 along the longitudinal abutting edges 19, 21 of the half sections 12, 14, the adjacent surfaces of the end walls 18, 20, 24, 26, and the cement on the interior surfaces 16 and 17 secure the half sections together and provide a smooth continuous lining for the sample cavity 23. A refractory disc 34 is positioned at the end of the handle 32 to prevent entry of molten metal into the handle and provide a smooth sample end. When the refractory cement lining 35 dries, the entire assembly is dipped into refractory cement to provide a non-consumable and non-combustible, non-skulling exterior refractory cement coating around the handle 32 and the exterior surfaces of the cartridge 11. An entry port 42 is then cut into a wall of the cartridge to afford entry of molten metal into the sample cavity 23. A fusible closure can be secured to the cartridge 11 with refractory cement in overlapping relation across the entry port 42 to prevent entry of slag into the port 42 as the lance is lowered through the slag layer.

FIG. 4 shows a modified embodiment with the cartridge 11 provided with a smooth steel liner which has an end 52 adjacent the end walls 18, 20 and a tapered or oblique end 54 which extends past the entry port 42. The tapered end 54 thus enables flow of metal through the entry port into the interior of the liner and the projecting liner end 54 protects and strengthens the wall portion 58 opposite the entry port 42. The liner 50 provides a sample with a smooth surface and provides FIG. 6 is a longitudinal sectional; view of an additional embodiment of the invention.

FIG. 7 is a sectional view along line 77 of FIG. 6.

DETAILED DESCRIPTION OF THE DRAWINGS In FIG. 1, the sampling lance 10 includes a frangible sample cartridge 11 formed from molded sand half sections 12 and 14 formed from resin coated refractory sand. In the disclosed embodiment the sections 12 and 14 are in the form of semi-cylindrical wall portions with exterior surfaces respectively 13 and 15, and concave interior surfaces 16 and 17. The interior surfaces 16 and 17 define a sample cavity 23. The half sections 12 and 14 include semicircular end portions or walls 18 and 20 and end portions or walls 24 and 26. The end walls 24 and 26 have an axial thickness greater than the end walls 18 and 20 and have longitudinal grooves 30. The longitudinal grooves 30 receive a handle or pipe 32 which has a flared end 31 which retains the handle in the cartridge 11.

additional strength and rigidity to the cartridge.

FIG. 5 includes a further embodiment of the invention in which the refractory cartridge 66 has a continuous cylindrical wall 68 which is molded around a handle 70. An end wall or plug 72 seals the sample cavity 74. The sand cast cartridge is then dipped in a slurry of refractory cement to provide an exterior refractory coating 76 and an interior refractory coating 78. The refractory coatings 76 and 78 afi'ord the desired rigidity for the sand cast cylindrical wall 68. A side entry port 78 can be formed after the interior and exterior walls are coated.

FIG. 6 shows a further embodiment of the cartridge 79 with a continuous cylindrical wall 80 constructed of molded refractory sand with an exterior refractory cement coating 82 and an interior refractory cement coating 84 formed by dipping the cartridge into a slurry of refractory cement. An end wall 86 can then be cemented at the end of the cavity 87 with refractory cement. The end wall 86 can be provided with a fused quartz inlet and pin sample tube 88 connected to a sample mold 90. A fusible cap 92 can cover the tube 88 to prevent entry of slag as the cartridge is lowered into a molten metal bath.

The sample cartridges of the invention have a long immersion life and are relatively inert as compared with various prior art sampling devices which employ cardboard sleeve, and accordingly, there is a minimum of boiling and spattering of metal in the bath when the lance is inserted. The sand cast cartridges provide easy sample release and the refractory coating on the exterior of the cartridge minimizes skulling on the cartridge which interferes with recovery of the sample. The refractory lining in the sample cavity provides samples of the appropriate size and shape with a smooth exterior surface which can be sliced for spectographic analysis without any further machining operation.

I claim:

1. A molten metal sampling device comprising a sample cartridge having two molded frangible half sections with exterior surfaces and interior surfaces defining a sample cavity, a refractory lining on said interior surfaces, a refractory coating on the exterior surfaces of said half sections, and a sample entry port in said cartridge for communicating with said sample cavity for admitting a sample of molten metal into said sample cavity.

2. A device in accordance with claim 1 wherein said half sections are molded from foundry sand.

3. A molten metal sampling device comprising two molded sand half sections having concave wall portions forming a sample cavity, a refractory cement lining on said concave wall portions forming a smooth, continuous interior surface, a refractory cement coating on the exterior surface of said half sections to maintain the integrity of said sections during immersion of the device in a molten metal bath, and a sample entry port in one of said wall portions.

4. A device in accordance with claim 3 wherein said half sections have semi-circular end portions which define end walls of the sample cavity.

5. A device in accordance with claim 3 wherein said half sections have end walls with longitudinal grooves for receiving a handle.

6. A device in accordance with claim 5 including a handle in said grooves, said handle having a flared end located within the sample cavity to secure said handle to said cartridge.

7. A device in accordance with claim 6 including a refractory disc in said sample cavity located against said handle end.

8. A sample cartridge for sampling molten metal comprising a molded refractory sand wall having interior and exterior surfaces defining a sample cavity, a refractory cement lining on said interior surface and a refractory cement coating on the exterior surface to maintain the integrity of said wall when immersed in the molten metal bath and an aperture in said wall communicating with said sample cavity for entry of molten metal into said cavity. 

1. A molten metal sampling device comprising a sample cartridge having two molded frangible half sections with exterior surfaces and interior surfaces defining a sample cavity, a refractory lining on said interior surfaces, a refractory coating on the exterior surfaces of said half sections, and a sample entry port in said cartRidge for communicating with said sample cavity for admitting a sample of molten metal into said sample cavity.
 2. A device in accordance with claim 1 wherein said half sections are molded from foundry sand.
 3. A molten metal sampling device comprising two molded sand half sections having concave wall portions forming a sample cavity, a refractory cement lining on said concave wall portions forming a smooth, continuous interior surface, a refractory cement coating on the exterior surface of said half sections to maintain the integrity of said sections during immersion of the device in a molten metal bath, and a sample entry port in one of said wall portions.
 4. A device in accordance with claim 3 wherein said half sections have semi-circular end portions which define end walls of the sample cavity.
 5. A device in accordance with claim 3 wherein said half sections have end walls with longitudinal grooves for receiving a handle.
 6. A device in accordance with claim 5 including a handle in said grooves, said handle having a flared end located within the sample cavity to secure said handle to said cartridge.
 7. A device in accordance with claim 6 including a refractory disc in said sample cavity located against said handle end.
 8. A sample cartridge for sampling molten metal comprising a molded refractory sand wall having interior and exterior surfaces defining a sample cavity, a refractory cement lining on said interior surface and a refractory cement coating on the exterior surface to maintain the integrity of said wall when immersed in the molten metal bath and an aperture in said wall communicating with said sample cavity for entry of molten metal into said cavity. 